Personal Communication Services ("PCS") describes systems and services which enable a user to communicate anytime, anywhere, and in any form. The basic structure is to allocate a single ID called a Universal Personal Telecommunication (UPT) number to a device allowing voice and data communication of any kind, any time, and anywhere in the world. Because PCS is digital, it can handle data, messaging, paging, and in the future, full multimedia access--besides regular voice telephony--all with one device and one UPT.
A PCS communications system is disclosed in U.S. Pat. No. 5,481,546 to Dinkins. The Dinkins patent discloses an interactive nationwide data service communication system for stationary and mobile battery operated subscriber units that transmit digital communications in the milliwatt power range and contemplates utilization of VBI to send messages; however, the Dinkins system contemplates a plurality of receive-only base stations and local base station repeater cell means distributed throughout the designated area for relaying the low power digital messages within the network. Similarly, a system and method for providing microcellular PCS utilizing embedded switches is disclosed in U.S. Pat. No. 5,457,736 to Cain et al. The system, however, uses existing wireline switches to establish communications between the mobile terminals and an Advanced Intelligent Network. An asymmetric hybrid access system and method is disclosed in U.S. Pat. No. 5,586,121 to Maura et al. The system can utilize communication media to distribute to remote clients high speed data packets on a downstream channel and to transmit return data along an independent upstream channel at a lower speed than the data packet rate transmitted in the downstream channel. The communication media for each of the upstream and downstream channels is selected from one of a CATV distribution network, a cell site, a television transmitter station, a fiber optic network, a wireless network, a telephone network or a satellite communication network. The system is limited in providing full-duplex interactive asymmetric communications between the host server and a plurality of downstream clients using independent upstream channels. However, the known PCS systems do not disclose the concept of utilizing the existing VBI band width for voice (fixed or mobile) along with the technology for return signal processing and signal finessing of the present invention.
Additionally, the enhanced PCS system of the present invention features the receiving of the messaging or PCS information on the VBI carrier by a mobile transceiver, which can retransmit the PCS or return data information on the same carrier to the return signal processor. Finally, the enhanced PCS system of the present invention also features acquiring of the return signal having such message and PCS information on the carrier by the return signal processor, whereby such features are performed at low power and are not disclosed in the prior art.
Additional existing TV data broadcasting communication systems can utilize either the horizontal blanking interval ("HBI") or the vertical blanking interval ("VBI") of the TV signal to deliver point-to-multipoint data delivery, for example, when information is being transmitted simultaneously to many locations. VBI data broadcasting can deliver data simultaneously and at high speed to anyone who needs such information as news, stock quotes, weather radar images, road and traffic conditions and closed captioned text. A standard North American television signal consists of 525 horizontal lines divided into two fields each with 262.5 lines. The first 21 lines of each field comprise the Vertical Blanking Interval ("VBI"); lines 1 to 9 of the VBI are for timing and sequencing; lines 10 through 21 are not allocated, however, line 21 typically has been used to deliver closed caption information to the hearing impaired (via a decoder unit) everywhere the television signal can be received. Therefore, VBI broadcasting uses lines 10 to 20 of the VBI to transport nearly any type of data along with the Several Television data broadcasting systems are known for delivering certain forms of data over a standard TV signal. One such system is the North American Basic Teletext Specification (NABTS) that provides an open standard for the transmission of data over the television, which system equipment is manufactured by Norpak Corporation, Kanata, Ontario. Another system is being offered by Radio Telephone and Television Corporation. As the data is encoded as video it becomes an integral part of the TV signal and, thus, the VBI data is transmitted everywhere that the television signal reaches and furthermore can pass transparently through all carrier media (VHF, UHF, cable, satellite, wireless cable, BTV networks, fiber optic cable, ITFS, etc.). Known VBI systems include a data insertion system at the television network "head end" and an inexpensive VBI data or graphics receiver at each site.
Because VBI data broadcasting only transmits data in only one direction, i.e., high speed, one-way, point-to-multipoint data transmission medium, there is a longfelt need for two-way VBI data broadcasting. As is more fully described herein, the present invention provides such a two-way communication system that utilizes the VBI of the television signal. A VBI data broadcasting system is disclosed in U.S. Pat. No. 5,321,514 to Martinez. The Martinez patent discloses an interactive television and data transmission system that provides transmission of information to multiple users. However, the Martinez patent uses a second carrier for transmitting the down link signals on either the horizontal or vertical blanking intervals and another carrier for transmitting uplink signals.